2021 Sur-Ron X: Everything You Need To Know

surron electric bike
Surron Electric Bike

We’ve all heard it: The old adage that goes something like: “Fast, affordable, and lightweight… Pick two.” But after a thorough review of the latest Sur-Ron X, it seems there’s an exception to the rule.

The original Sur-Ron electric motorcycle launched in 2018, and it didn’t take long to peak the public’s interest. Eight inches of suspension travel and a 45mph top speed? For $3500? Please, take my money.

Within the first year, the Sur-Ron’s popularity skyrocketed. It was easy to ride and even easier to modify, and quickly developed a dedicated cult following.

Now in its fourth year of production, the latest model is the Sur-Ron X, which comes with more options and upgrades than ever. The price is up a little ($4,100 when ordered direct from US distributor Luna Cycles), but so is the performance.

In the article below we’ll look at the latest model for 2021, as well as its performance and components. We’ll cover some of the most popular upgrades as well (both factory and aftermarket) for anyone interested in purchasing or upgrading one of these high-speed dirt slayers.

surron road legal
Surron LB road legal

Overview

The Sur-Ron X is made in China, but the build quality suggests otherwise.

The aluminum alloy frame and swingarm are solid but light, and help keep the bike’s weight down around 100 pounds.

19-inch wheels are equipped front and rear and are shod in fairly aggressive 110/70 knobby tires. Sur-Ron branded 4-piston hydraulic brakes round out the whole package front and rear, both clamping down on 203mm rotors.

The cockpit is clean and simple. Throttle and brakes are on the right, while a digital speedometer, power mode selector, and second brake lever live on the left.

Bright LED lighting comes standard both front and rear, although both lights are constantly on and can’t be switched off.

The 2021 model shares most of its components with the original Sur-Ron, with a few notable upgrades. The latest Sine Wave controller is the most significant, boosting power by 25% and enabling regenerative coasting/braking. An improved headset, bar, and grips are also included in the package.

Sur-Ron X Performance

As mentioned above, the “Sine Wave” electronic controller is the stand out performance upgrade for 2021.

This controller was previously only offered as a $500 upgrade, and boosts power and top speed while also smoothing out power delivery.

That new controller, combined with the 60v/32A Panasonic battery pushes the top speed up to 48 miles an hour. That’s just two mph shy of the latest KTM Freeride by the way, which is currently retailing for over $11,000.

All that power is delivered to the rear wheel via a direct drive motor with a claimed 18 ft lbs of torque. Final drive duties are handled by a sealed o-ring chain and 48-tooth rear sprocket, but belt drive kits are available too as we’ll discuss below.

Two power modes are available for 2021: “Sport” which gives riders access to the full 7000 watts of peak power, and “Eco” which focuses on efficiency for maximum range.

Speaking of range you can expect to get roughly two full hours of play time in Sport mode. Depending on how hard you push it and what kind of terrain you ride (this bike doesn’t love climbing hills) that’s going to land you somewhere between 20-25 miles on a full charge.

Eco mode, on the other hand, cuts your top speed down to around 15 mph, but nets you between 50 and 60 miles on a full charge depending on how much you use the regenerative coasting/braking option.

surron white
Sur-Ron 2021 Light Bee LB X-Series

Sur-Ron X Suspension

Most Sur-Ron X models ship with either a DNM Volcano USD8 or RST Killah dual crown front fork. These two are more or less interchangeable in terms of performance, and that’s not a good thing.

While both forks include a full 8” of travel and are fully adjustable for compression and rebound, we’ve found that they both suffer from a serious lack of damping, are prone to bottoming out under serious off-road use, and have little to no small bump sensitivity.

That’s not a big deal if the majority of your riding takes place on pavement. However, if you like fast singletrack or hitting jumps, your fork will need some love.

We’ve done extensive testing on fork options for the Sur-Ron, Motopeds, and other heavier eBikes and you can read that article here.

The DNM Burner rear shock is fully adjustable as well, but ultimately suffers from the same lack of damping.

No need to replace it though, as the Burner can be revalved by a good suspension shop for under $200. That’s good news for Sur-Ron owners considering half the appeal of the bike is its price-to-fun ratio.

Recommended Upgrades For The Sur-Ron X

Luna Cycles heard the prayers of their fans and started adding some crucial items to their parts catalog in 2020.

Here are the upgrades we recommend, both direct from Luna and aftermarket as well.

Suspension

Aside from the limited run of “black editions” that Luna Cycles sold with a Rockshox Boxxer fork, the front end of any Sur-Ron X is its major weakness.

Whether you get the DNM USD8 or the RST Killah version depends on when you order your bike, but either way, you’re going to want to do something about it sooner than later.

We’ve done rigorous in-depth testing of the most popular suspension options out there for the Sur-Ron, so if you’re interested in upgrading the front fork (as most owners are), again, check out our separate article on the topic.

Tires

Most owners opt for a dedicated dirtbike tire rather than the no-name motorcycle/mountain bike hybrid that comes on the bike.

Your options are limited by your wheel size (read more below), but since the factory rims are both the same 19-inch diameter, there are a few solid dirtbike tires out there to choose from.

The Pirelli Scorpion MX32 is a favorite from the motocross world for soft and intermediate terrain and has plenty of teeth for everything from loam to deep sand.

If you’re interested in a tougher compound or prefer more of an all-rounder, the Shinko SR241 is a great alternative to the Pirelli. Opting for a Shinko also saves you money, although tracking down one in the required 2.75×19 size is tricky.

Wheels

If you’re riding your Sur-Ron X offroad, it won’t take long for you to start breaking spokes and bending hoops on the stock wheels.

For aggressive riders, swapping out the stock 19” hoops with stronger dirtbike wheels is a must.

Most folks will want to look into switching to traditional dirtbike sizes while they’re at it. A 21” front wheel and 18” rear will perform better offroad and give you a much larger selection of tires.

Cockpit Upgrades

The ergonomics of the Sur-Ron X are fairly comfortable for day-to-day use, but when you’re moving around and standing up on the bike offroad, it starts feeling awfully small.

Adding around a 3” rise between your handlebar and stem from dirtbike brands like Renthal or Protaper will make a world of difference in both comfort and handling offroad.

This also gives you a chance to run your dirtbike grip of choice. I’ve always been a fan of the Renthal road race firm grips, but most folks swear by ProTaper pillow tops for everything from trail riding to motocross.

Brakes

The Sur-Ron branded brake calipers are decent quality from the factory, but the brake pads themselves feel vague and underpowered.

Swapping out your pads with sintered or semi-metallic pads like Shimano’s “Saint” line makes a huge difference in your stopping power and feel at the lever.

Of course, if that still isn’t enough for you, upgrading the entire brake system to a Magura kit like the MT5 found on the Stealth B52  will definitely do the trick.

Electronic Throttle

The cable-driven throttle that comes on the Sur-Ron X is decent, and initially shouldn’t give you any problems. Many riders are reporting that after a few hundred miles, however, they start sticking and become a liability.

For this reason, swapping out an electronic throttle at your first opportunity is a popular upgrade for Sur-Ron owners. Luna Cycles offers an in-house upgrade kit for this mod, as well as an aftermarket Magura version that drastically changes the throttle operation and sensitivity.

Belt Drive Conversions

For 99% of Sur-Ron owners, swapping out the chain and sprocket setup for a belt drive is a no-brainer.

The belt system weighs 1.4 pounds less, is nearly silent even at high speeds, and requires zero maintenance.

Luna Cycles claims their Gates belt kit will last the life of the bike with a few exceptions.

Motocross riders, for example, should stick with the chain and sprocket setup due to the aggressive nature of the sport.

Stunt riders should stick to the chain as well, as Luna warns quick wheelies from full stop will likely snap a belt.

But, if you’re not doing either of those activities, and you haven’t tuned your Sur-Ron X up over 20,000 watts of power, the belt drive is a win-win.